Darolutamide is a potent androgen receptor antagonist with strong efficacy in prostate cancer models

Abstract

Darolutamide is a novel androgen receptor (AR) antagonist with a distinct chemical structure compared to other AR antagonists and currently in clinical Phase 3 trials for prostate cancer. Using cell‐based transactivation assays, we demonstrate that darolutamide, its diastereomers and its main metabolite keto‐darolutamide are strong, competitive antagonists for AR wild type, and also for several mutants identified in prostate cancer patients for which other AR antagonists show reduced antagonism or even agonism. Darolutamide, its two diastereomers and main metabolite are also strong antagonists in assays measuring AR N/C interaction and homodimerization. Molecular modeling suggests that the flexibility of darolutamide allows accommodation in the W742C/L mutated AR ligand‐binding pocket while for enzalutamide the loss of the important hydrophobic interaction with W742 leads to reduced AR interaction. This correlates with an antagonistic pattern profile of coregulator recruitment for darolutamide. In vitro efficacy studies performed with androgen‐dependent prostate cancer cell lines show that darolutamide strongly reduces cell viability and potently inhibits spheroid formation. Also, a marked down‐regulation of androgen target genes paralleled by decreased AR binding to gene regulatory regions is seen. In vivo studies reveal that oral dosing of darolutamide markedly reduces growth of the LAPC‐4 cell line‐derived xenograft and of the KuCaP‐1 patient‐derived xenograft. Altogether, these results substantiate a unique antagonistic profile of darolutamide and support further development as a prostate cancer drug.

Darolutamide antagonizes androgen signaling by blocking enhancer and super‐enhancer activation

“…Following treatment of R1881-stimulated VCaP or LAPC4 cells with the AR antagonist darolutamide, we observed decreased proliferation and changed morphology compared to R1881 treatment alone, as expected (Sugawara et al, 2019) (Fig. 1A).…”

“…VCaP and LAPC4 cells were purchased from the American Type Culture Collection (ATCC, Manassas, VA, USA) and the Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ, Braunschweig, Germany). Cells were routinely cultured as described previously (Sugawara et al, 2019;Sugawara et al, 2016). They were stimulated with the synthetic androgen R1881 at a concentration of 1 nM after 2 days of starvation in medium supplemented with 10% charcoal-stripped FBS.…”

“…Darolutamide is a novel AR antagonist recently approved for nonmetastatic castration-resistant PCa patients by the American Food and Drug Administration (Fizazi et al, 2019). Darolutamide binds with high affinity to the ligand-binding pocket of the AR and efficiently blocks homodimerization of the AR (Moilanen et al, 2015;Sugawara et al, 2019). It inhibits AR translocation into the nucleus, thus leading to reduction of androgen target gene expression and ultimately decreasing proliferation of PCa cells (Moilanen et al, 2015).…”

“…It inhibits AR translocation into the nucleus, thus leading to reduction of androgen target gene expression and ultimately decreasing proliferation of PCa cells (Moilanen et al, 2015). This translates into high antitumor efficacy in vivo for different cell line-and patient-derived PCa models (Borgmann et al, 2018;Moilanen et al, 2015;Sugawara et al, 2019). Genome-wide studies on the effects of darolutamide on AR signaling have not been performed yet and would give novel insights into the regulatory network affected by this novel compound.…”

AKR1C3 mediates pan‐AR antagonist resistance in castration‐resistant prostate cancer

“…JNJ‐pan‐AR is a small molecule inhibitor with potent activity against wild‐type AR and AR mutants including, L701H, W741C, T877A, H874Y, and F876L. Currently, there are several pan‐AR antagonists in clinical development or approved for the treatment of CRPC harboring pathogenic point mutations in the AR ligand‐binding domain 8‐10 . While pan‐AR antagonists have the potential to meet the clinical needs of CRPC patients that no longer respond to second‐generation antiandrogens, it remains unclear if patients will go on to develop alternative resistance mechanisms through chronic exposure.…”